CN114713942A - Tungsten electrode argon arc additive manufacturing method based on negative pressure constraint of electric arc - Google Patents
Tungsten electrode argon arc additive manufacturing method based on negative pressure constraint of electric arc Download PDFInfo
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 136
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- 229910052786 argon Inorganic materials 0.000 title claims abstract description 90
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- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 title claims abstract description 37
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- NGONBPOYDYSZDR-UHFFFAOYSA-N [Ar].[W] Chemical compound [Ar].[W] NGONBPOYDYSZDR-UHFFFAOYSA-N 0.000 description 6
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/04—Welding for other purposes than joining, e.g. built-up welding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/08—Arrangements or circuits for magnetic control of the arc
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
- B23K9/167—Arc welding or cutting making use of shielding gas and of a non-consumable electrode
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/32—Accessories
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
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Abstract
The invention discloses an electric arc negative pressure constraint argon tungsten-arc additive manufacturing method, which comprises the following steps: arranging an electrified coil outside the welding nozzle or the welding gun to form a longitudinal magnetic field with the center line of the magnetic field parallel to or coincident with the center line of the electric arc; adjusting the magnetic field intensity of the longitudinal magnetic field to enable the magnetic field intensity to be larger than a set critical value, and taking the magnetic field intensity larger than the critical value as a target magnetic field intensity; the longitudinal magnetic field with the magnetic field intensity reaching the target magnetic field intensity acts on the welding electric arc, so that the direction of electric arc force is opposite to the direction of gravity, and further the electric arc negative pressure constraint is formed; feeding the welding wire into the welding area at a set included angle, so that the welding wire is melted in the welding arc area, and performing the tungsten electrode argon arc welding fuse wire additive manufacturing process under the action of negative pressure of the arc; the invention can effectively control the tungsten electrode argon arc welding fuse wire additive manufacturing process, improves the precision, the efficiency and the performance, and provides a new method for the modern electric arc additive manufacturing technology.
Description
Technical Field
The invention relates to the field of additive manufacturing, in particular to a tungsten electrode argon arc additive manufacturing method with negative pressure restriction of an electric arc.
Background
In the conventional argon tungsten-arc additive manufacturing process, a welding arc is a plasma, a plasma flow force formed by the welding arc plasma is a welding arc force, the welding arc force is an axial impact force generated by a high-speed moving plasma fluid in the welding arc, and in the conventional argon tungsten-arc welding fuse additive manufacturing process, the welding arc force is always an axial positive pressure relative to a welding molten pool, so that under the conventional argon tungsten-arc welding fuse additive manufacturing condition, the welding molten pool generates a liquid level difference and generates a phenomenon of sinking and the like due to the fact that the arc positive pressure acts on the surface of the welding molten pool.
Under the condition of additive manufacturing of a conventional argon tungsten-arc welding fuse wire, the positive arc pressure not only directly influences the movement condition of a melt in a molten pool, but also has dominating effects on molten drop transition, the cross section shape of the molten pool, a welding seam solidification structure and joint quality, and particularly causes many adverse phenomena of discontinuous welding seams, humping and the like during high-speed and high-efficiency additive manufacturing, and simultaneously influences the additive manufacturing efficiency and the joint performance of the argon tungsten-arc welding fuse wire.
Disclosure of Invention
In view of this, the invention aims to overcome the defects in the prior art, and provides an argon tungsten-arc additive manufacturing method with negative arc pressure constraint, which can effectively control the argon tungsten-arc welding fuse additive manufacturing process, improve the precision, efficiency and performance, and provide a new method for the modern electric arc additive manufacturing technology.
The invention relates to an electric arc negative pressure constraint argon tungsten-arc additive manufacturing method, which comprises the following steps:
arranging an electrified coil outside the welding nozzle or the welding gun to form a longitudinal magnetic field with the center line of the magnetic field parallel to or coincident with the center line of the electric arc;
adjusting the magnetic field intensity of a longitudinal magnetic field, combining with the parameters of the conventional tungsten electrode argon arc additive manufacturing process, enabling the magnetic field intensity to be larger than a critical value required to be set under the condition of the electric arc negative pressure constraint tungsten electrode argon arc additive manufacturing process, and taking the magnetic field intensity larger than the critical value as a target magnetic field intensity;
the longitudinal magnetic field with the magnetic field intensity reaching the target magnetic field intensity acts on the electric arc, so that the direction of electric arc force is opposite to the direction of gravity, the electric arc force is promoted to be converted from positive pressure to negative pressure, and the electric arc negative pressure constraint tungsten electrode argon arc additive manufacturing process is further formed;
feeding the welding wire into the welding area at a set included angle, so that the welding wire is melted in the welding arc area, and performing the tungsten electrode argon arc welding fuse wire additive manufacturing process under the action of negative pressure of the arc; the included angle is the included angle between the welding wire and the welding direction.
Further, the electrified coil adopts an air coil which is a spirally wound coil, an iron core and a cooling structure are arranged in the coil, the cooling structure ensures that the coil can normally work under the condition of high-temperature welding environment, the air coil is arranged outside a welding nozzle or a welding gun, or the air coil and the welding gun or the welding gun are integrated into a whole, a compact integrated structure of the external magnetic field-welding gun or the welding gun is formed, and exciting current is applied to the air coil to form a manufacturing mode of the fuse wire additive manufacturing of the external longitudinal magnetic field composite tungsten electrode argon arc welding.
Further, the waveform, direction, frequency and amplitude of the exciting current can be adjusted or set; the exciting current comprises direct current, alternating current, pulse and variable polarity.
Further, the magnetic field direction of the longitudinal magnetic field is axially parallel to or coincident with the arc center; the longitudinal magnetic field is one of a gap alternating longitudinal magnetic field, a constant longitudinal magnetic field, a pulse longitudinal magnetic field, a sine wave longitudinal magnetic field and an alternating longitudinal magnetic field.
Further, the duty ratio of the gap alternating longitudinal magnetic field is 10-60%, and the frequency of the gap alternating longitudinal magnetic field is 1-30 Hz.
Further, the included angle ranges from 15 degrees to 80 degrees, and a welding wire is fed into a welding area in a paraxial wire feeding mode; according to the performance of the additive manufacturing material, a hot wire or cold wire mode is adopted to feed the welding wire into a welding area; the welding wire is one of a solid welding wire, a flux-cored welding wire and a powder-cored welding wire.
Further, the argon tungsten-arc additive manufacturing method comprises the following process parameters: the diameter of a tungsten electrode is 1.2-6 mm, the additive manufacturing current is 40-450A, the length of an additive manufacturing electric arc is 1-4.8 mm, the additive manufacturing voltage is 8-65V, the additive manufacturing speed is 10-600 cm/min, the diameter of an additive manufacturing welding wire is 0.6-4.0 mm, the additive manufacturing wire feeding speed is 10-800 cm/min, the additive manufacturing efficiency is 0.1-5 Kg/h, the flow rate of a protective gas is 10-80L/min, the protective gas is one of mixed gases of 99.99% argon, 99.99% helium, 99.99% argon and 99.99% helium, and the interlayer temperature of additive manufacturing is controlled to be 100-400 ℃.
Further, when the additive manufacturing current is 100A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.02T, and the arc pressure of the arc center is 0 Pa;
when the additive manufacturing current is 120A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.022T, and the arc pressure of the arc center is 0 Pa;
when the additive manufacturing current is 150A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.026T, and the arc pressure of the arc center is 0 Pa.
Further, the electric arc force of the electric arc is attractive, the molten drops are subjected to molten drop transition under the action of the electric arc attractive force, the electric arc has the attractive effect on a molten pool, and the electric arc is used for additive manufacturing of low-carbon steel, alloy steel, stainless steel, armor steel, bearing steel, die steel, aluminum alloy, titanium alloy, magnesium alloy, copper alloy, high-temperature alloy, high-entropy alloy, refractory metal and single crystal material.
The invention has the beneficial effects that: the invention discloses an arc negative pressure constraint argon tungsten-arc additive manufacturing method, which realizes the arc negative pressure by using an external magnetic field and Lorentz force generated by welding arc, fuse welding molten drop and current distributed in a welding pool, can effectively control the forming formability of argon tungsten-arc welding fuse additive manufacturing, is beneficial to establishing an arc negative pressure constraint arc welding fuse additive manufacturing scientific and technical system, provides a new method for the modern arc additive manufacturing technology, produces original achievements of the argon tungsten-arc welding fuse additive manufacturing scientific and technical system based on the arc negative pressure constraint from scratch, and has higher engineering application value.
Drawings
The invention is further described below with reference to the following figures and examples:
FIG. 1 is a schematic view of the principle of negative-pressure electric arc tungsten argon arc additive manufacturing of the present invention;
FIG. 2 is a schematic diagram of the manufacturing principle of positive-pressure argon tungsten-arc welding with electric arc according to the present invention;
wherein, 1-tungsten electrode, 2-electric arc negative pressure, 3-molten pool, 4-workpiece, 5-molten pool surface, 6-welding electric arc, 7-welding wire and 8-electric arc positive pressure.
Detailed Description
The invention is further described with reference to the accompanying drawings, in which:
the invention relates to an electric arc negative pressure constraint argon tungsten-arc additive manufacturing method, which adopts an external longitudinal magnetic field to control an argon tungsten-arc welding electric arc, promotes the electric arc to form electric arc negative pressure, and forms the electric arc negative pressure constraint argon tungsten-arc additive manufacturing method; the method comprises the following steps:
arranging an electrified coil outside the welding nozzle or the welding gun to form a longitudinal magnetic field with the center line of the magnetic field parallel to or coincident with the center line of the electric arc;
adjusting the magnetic field intensity of a longitudinal magnetic field, combining with the parameters of the conventional tungsten electrode argon arc additive manufacturing process, enabling the magnetic field intensity to be larger than a critical value required to be set under the condition of the electric arc negative pressure constraint tungsten electrode argon arc additive manufacturing process, and taking the magnetic field intensity larger than the critical value as a target magnetic field intensity;
the longitudinal magnetic field with the magnetic field intensity reaching the target magnetic field intensity acts on the electric arc, so that the direction of electric arc force is opposite to the direction of gravity, the electric arc force is promoted to be converted from positive pressure to negative pressure, and the electric arc negative pressure constraint tungsten electrode argon arc additive manufacturing process is further formed;
feeding the welding wire into the welding area at a set included angle, so that the welding wire is melted in the welding arc area, and performing the tungsten electrode argon arc welding fuse wire additive manufacturing process under the action of negative pressure of the arc; the included angle is the included angle between the welding wire and the welding direction.
The invention adopts an external longitudinal magnetic field mode to induce the welding electric arc to generate electric arc negative pressure phenomenon in the tungsten electrode argon arc welding fuse wire additive manufacturing process, maintains the stable operation of electric arc and molten drop transition in the tungsten electrode argon arc welding fuse wire additive manufacturing process of electric arc negative pressure through an electromagnetic thermal comprehensive means, and forms a new tungsten electrode argon arc welding fuse wire additive manufacturing process with the characteristic of generating electric arc negative pressure by an external longitudinal magnetic field; the method can effectively solve the problem that the arc positive pressure acts on the surface of the welding molten pool to generate depressions, eliminate the influence of the motion behavior of the wall surface and the internal fluid of the molten pool, the solidification forming state and the fuse droplet transition, and solve the problems of poor weld forming, particularly the difficult problems of the fuse droplet transition stability, the molten pool stability and the shape control performance thereof under the high-speed and high-efficiency welding technical condition.
In this embodiment, the electrified coil is an air coil, the air coil is a spirally wound coil, an iron core and a cooling structure are arranged in the coil, the cooling structure ensures that the coil can normally work under the welding high-temperature environment condition, the air coil is installed outside a welding nozzle or a welding gun, or the air coil and the welding gun or the welding gun are integrated into a whole, a compact integrated structure of an external magnetic field-welding gun or the welding gun is formed, and exciting current is applied to the air coil to form an external longitudinal magnetic field composite tungsten electrode argon arc welding fuse wire additive manufacturing mode. Applying various exciting currents on a spiral lead of the hollow coil by using a digital multifunctional multi-waveform exciting power supply to form a corresponding external longitudinal magnetic field; of course, other existing magnetic field generating devices can be used to implement the external longitudinal magnetic field, and are not described herein again.
In this embodiment, the excitation current includes dc, ac, pulse, and variable polarity. In order to enable a free adjustment or setting of the magnetic field direction and the magnetic field strength of the longitudinal magnetic field, the waveform, direction, frequency and amplitude of the excitation current are adjustable or settable.
In this embodiment, the magnetic field direction of the longitudinal magnetic field is axially parallel to or coincident with the arc center; through the arrangement, a corresponding external longitudinal magnetic field can be formed, the tungsten electrode argon arc welding fuse wire additive manufacturing electric arc is effectively controlled to form an electric arc negative pressure state, and the adsorption effect of the welding electric arc on fuse wire welding molten drops and molten pool antigravity is fully exerted. The longitudinal magnetic field is one of a gap alternating longitudinal magnetic field, a constant longitudinal magnetic field, a pulse longitudinal magnetic field, a sine wave longitudinal magnetic field and an alternating longitudinal magnetic field. The duty ratio of the gap alternating longitudinal magnetic field is 10-60%, and the frequency of the gap alternating longitudinal magnetic field is 1-30 Hz.
In the embodiment, the included angle ranges from 15 degrees to 80 degrees, and the welding wire is fed into a welding area in a paraxial wire feeding mode; according to the performance of the additive manufacturing material, a hot wire or cold wire mode is adopted to feed the welding wire into a welding area; the welding wire is one of a solid welding wire, a flux-cored welding wire and a powder-cored welding wire. In the wire feeding process of the side shaft, if the included angle between the welding wire and the welding direction is too large or too small, the solidified structure and the joint quality of the welding line can be influenced, so that the welding line is further discontinuous, the joint performance is further reduced, the included angle between the welding wire and the welding direction is kept within the angle range of 15-80 degrees, and the welding line effect and the joint performance can be further improved.
In the embodiment, according to the used materials and the additive manufacturing process parameters of the tungsten argon arc welding fuse wire, the strength of an external longitudinal magnetic field needs to exceed a critical value matched with the welding process parameters, so that the electric arc of the additive manufacturing of the tungsten argon arc welding fuse wire is formed into the negative electric arc pressure, the welding electric arc plasma generates regular and stable self-rotation motion in the negative electric arc pressure state, the electric arc plasma displays the reverse motion behavior from a sample to an electrode, and the welding electric arc shows the characteristic attraction force which is different from the conventional tungsten argon arc welding on a fuse wire welding droplet and a welding molten pool, so that the additive manufacturing of the tungsten argon arc welding fuse wire based on the basic characteristic of the negative electric arc pressure is realized on the metal materials, and the new additive manufacturing technology of the tungsten argon arc welding fuse wire based on the negative electric arc pressure constraint is formed.
The argon tungsten-arc additive manufacturing method comprises the following process parameters: the diameter of a tungsten electrode is 1.2-6 mm, the additive manufacturing current is 20-450A, the length of an additive manufacturing electric arc is 1-4.8 mm, the additive manufacturing voltage is 8-65V, the additive manufacturing speed is 10-600 cm/min, the diameter of an additive manufacturing welding wire is 0.6-4.0 mm, the additive manufacturing wire feeding speed is 10-800 cm/min, the additive manufacturing efficiency is 0.1-5 Kg/h, the flow rate of a protective gas is 20-80L/min, the protective gas is one of mixed gases of 99.99% argon, 99.99% helium, 99.99% argon and 99.99% helium, and the interlayer temperature of additive manufacturing is controlled to be 100-400 ℃.
The critical value can be set according to the actual working condition, when the additive manufacturing current is 100A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.02T, and the arc pressure of the arc center is 0 Pa; namely, after the external field and the external longitudinal magnetic field strength exceed 0.02T, the stable manufacturing process of the fuse additive for the tungsten electrode argon arc welding can be formed under the constraint of the negative pressure of the electric arc;
under the conditions that other conditions are not changed, when the additive manufacturing current is 120A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.022T, and the arc pressure at the center of an arc is 0 Pa;
under other conditions, when the additive manufacturing current is 150A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.026T, and the arc pressure at the center of the arc is 0 Pa.
In this embodiment, the arc force of the arc is an attractive force, the direction of the arc force is opposite to that of gravity in a conventional position, the droplet is subjected to droplet transition under the action of the arc attractive force, and the arc has an attractive effect on a molten pool and is used for additive manufacturing of low-carbon steel, alloy steel, stainless steel, armored steel, bearing steel, die steel, aluminum alloy, titanium alloy, magnesium alloy, copper alloy, high-temperature alloy, high-entropy alloy, refractory metal and single crystal material.
The first embodiment of the additive manufacturing of the argon tungsten-arc welding fuse wire with negative arc pressure constraint is as follows: 99.99% argon protection, 8-20L/min argon flow, 100A welding current, 2-4 mm arc length, 3.2mm tungsten electrode diameter, 8mm nozzle inner diameter, 12.8V arc voltage, 0.02T critical value of external longitudinal magnetic field intensity, 0.024T optimal value of external longitudinal magnetic field intensity, 8Hz optimal value of magnetic field frequency, gap alternating longitudinal magnetic field, 25% optimal value of duty ratio, 22-30 cm/min welding speed, 160-200 cm/min wire feeding speed, 5A06 aluminum alloy base plate material for additive manufacturing, 20mm base plate thickness, 5A06 aluminum alloy welding wire material, 10-degree included angle between welding wire and the plane of the additive manufacturing base plate, side-axis cold wire feeding mode, 1.2mm welding wire diameter, 120 ℃ interlayer temperature, the welding process parameters form an electric arc negative pressure constraint tungsten electrode argon arc welding fuse wire additive manufacturing technology.
The second embodiment of the additive manufacturing of the argon tungsten-arc welding fuse wire with negative arc pressure constraint is as follows: 99.99% argon protection, 10-24L/min argon flow, 120A welding current, 2-4 mm arc length, 3.2mm tungsten electrode diameter, 18V arc voltage, 0.022T critical value of external longitudinal magnetic field intensity, 0.026T optimal value of external longitudinal magnetic field intensity, 12Hz optimal value of magnetic field frequency, 25% optimal value of duty ratio, 28-36 cm/min welding speed, 180-240 cm/min wire feeding speed, stainless steel 316L substrate material for additive manufacturing, 20mm substrate thickness, stainless steel 316L welding wire material, 15-degree included angle between welding wire and additive manufacturing substrate plane, wire feeding in a paraxial cold wire feeding mode, 1.6mm welding wire diameter, interlayer temperature controlled at 180 ℃, the welding process parameters form an argon tungsten-arc welding fuse wire additive manufacturing technology with negative arc pressure constraint.
The third embodiment of the additive manufacturing of the argon tungsten-arc welding fuse wire with negative arc pressure constraint is as follows: the method comprises the following steps of 99.99% argon protection, 12-20L/min argon flow, 150A welding current, 2-4 mm arc length, 3.2mm tungsten electrode diameter, 16V arc voltage, 0.026T critical value of external longitudinal magnetic field intensity, 0.027T optimal value of external longitudinal magnetic field intensity, 10Hz optimal value of magnetic field frequency, 25% optimal value of external longitudinal magnetic field intensity, 32-50 cm/min welding speed, 600-800 cm/min wire feeding speed, Q345 material of an additive manufacturing substrate, 10mm thickness of the substrate, nickel-based alloy Inconel625 welding wire material, 60-degree included angle between the welding wire and the plane of the additive manufacturing substrate, wire feeding in a side-axis cooling wire feeding mode, 1.2mm diameter of the welding wire, controlling interlayer temperature at 200 ℃, and forming an arc negative pressure constraint tungsten electrode argon arc welding fuse wire additive manufacturing technology by the welding process parameters.
The invention adopts an automatic welding robot and a 6-axis welding displacement welding platform, and is matched with a digital tungsten electrode argon arc welding power supply, a wire feeding mechanism, a gas protection and welding gun system to form tungsten electrode argon arc welding fuse wire additive manufacturing equipment with electric arc negative pressure constraint.
The difference characteristics of the argon tungsten-arc welding fuse wire additive manufacturing technology with the electric arc negative pressure constraint and the conventional external field composite argon tungsten-arc welding fuse wire additive manufacturing technology are that the external longitudinal magnetic field intensity must exceed the critical value matched with the parameters of the conventional argon tungsten-arc welding fuse wire additive manufacturing technology, namely the external magnetic field process parameter range of the argon tungsten-arc welding fuse wire additive manufacturing technology with the electric arc negative pressure constraint is not in the external magnetic field parameter range of the conventional external field composite argon tungsten-arc welding fuse wire additive manufacturing technology, the process characteristics of the argon tungsten-arc welding fuse wire additive manufacturing technology with the electric arc negative pressure constraint have the electric arc attraction (electric arc negative pressure action) which is not possessed by the conventional argon tungsten-arc welding fuse wire additive manufacturing technology (electric arc positive pressure) and the conventional external field composite argon tungsten-arc welding fuse wire additive manufacturing technology (electric arc positive pressure), and the argon tungsten-arc welding fuse wire additive manufacturing technology with the electric arc negative pressure constraint has the electric arc additive manufacturing technology with the conventional argon tungsten-arc welding fuse wire additive manufacturing technology (electric arc welding fuse wire negative pressure action) Arc positive pressure), welding thermal effect, welding force effect, droplet transition effect and welding momentum, quality and heat transfer behavior which are different from the conventional external field composite argon tungsten-arc welding fuse wire additive manufacturing technology (arc positive pressure), and the arc negative pressure of an external magnetic field has different electromagnetic stirring refined grains based on the arc negative pressure in the argon tungsten-arc welding fuse wire additive manufacturing process, and has the effect of improving the quality of welding seams.
The argon tungsten-arc welding fuse wire additive manufacturing technology based on the negative pressure constraint of the electric arc has the negative pressure effect of the additive manufacturing electric arc, when the electric arc manufactured by the argon tungsten-arc welding fuse wire additive manufacturing is under the negative pressure condition, the direction of the electric arc is opposite to the direction of gravity at the normal horizontal welding position, so the negative pressure effect is completely different from the condition that the electric arc force is the same (consistent) with the gravity direction in the conventional argon tungsten-arc welding fuse wire additive manufacturing, the research shows that the plasma of the welding electric arc presents the reverse motion characteristic under the technical condition of the invention, so the heat flow state of the welding electric arc to a welding molten pool is changed, the welding electric arc generates adsorption effect on the melt of the welding molten pool and the melt drops of the fuse wire welding, but the normal welding electric arc applies positive pressure effect on the melt of the molten pool, the melt of the welding molten pool is not excavated or repelled by the electric arc but is adsorbed and supported, the surface of a welding molten pool is naturally changed, the phenomena of molten pool tail solidification metal accumulation and hump generation caused by reasons of molten pool surface depression, bottom collapse and wall surface flow channel narrowing during conventional tungsten electrode argon arc welding, such as unsmooth flow of a melt to the tail of the molten pool, blocked backflow of the melt at the tail, insufficient heat flow transmission and the like are avoided, the stability of molten drop transition during fuse welding is improved, and the impact force of the molten drop is reduced.
And the change of the thermal characteristics and the distribution characteristics of the welding arc brings the change of the movement state of the melt of the molten pool, thereby influencing the solidification behavior of the welding seam and the formation characteristics of additive manufacturing, thus forming reasonable negative pressure restriction of the arc, namely the additive manufacturing heat effect of the argon tungsten-arc welding fuse wire, the negative pressure effect of the arc, the molten drop transition stabilizing mechanism, the molten pool stabilizing mechanism and the formation control technology of the additive manufacturing.
Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (9)
1. A tungsten electrode argon arc additive manufacturing method based on negative pressure constraint of electric arc is characterized in that: the method comprises the following steps:
arranging an electrified coil outside the welding nozzle or the welding gun to form a longitudinal magnetic field with the center line of the magnetic field parallel to or coincident with the center line of the electric arc;
adjusting the magnetic field intensity of a longitudinal magnetic field, combining with the parameters of the conventional tungsten electrode argon arc additive manufacturing process, enabling the magnetic field intensity to be larger than a critical value required to be set under the condition of the electric arc negative pressure constraint tungsten electrode argon arc additive manufacturing process, and taking the magnetic field intensity larger than the critical value as a target magnetic field intensity;
the longitudinal magnetic field with the magnetic field intensity reaching the target magnetic field intensity acts on the electric arc, so that the direction of electric arc force is opposite to the direction of gravity, the electric arc force is promoted to be converted from positive pressure to negative pressure, and the electric arc negative pressure constraint tungsten electrode argon arc additive manufacturing process is further formed;
feeding the welding wire into the welding area at a set included angle, so that the welding wire is melted in the welding arc area, and performing the tungsten electrode argon arc welding fuse wire additive manufacturing process under the action of negative pressure of the arc; the included angle is the included angle between the welding wire and the welding direction.
2. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 1, characterized in that: the electrified coil adopts an air coil, the air coil is a spirally wound coil, an iron core and a cooling structure are arranged in the coil, the cooling structure ensures that the coil can normally work under the condition of welding high-temperature environment, the air coil is arranged outside a welding nozzle or a welding gun, or the air coil and the welding gun or the welding gun are integrated into a whole, a compact integrated structure of an externally applied magnetic field-welding gun or welding gun is formed, and exciting current is applied to the air coil to form an externally applied longitudinal magnetic field composite tungsten electrode argon arc welding fuse wire additive manufacturing mode.
3. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 2, characterized in that: the waveform, direction, frequency and amplitude of the exciting current are adjustable or settable; the excitation current comprises direct current, alternating current, pulse and variable polarity.
4. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 1, characterized in that: the magnetic field direction of the longitudinal magnetic field is parallel to or coincident with the central axis of the electric arc; the longitudinal magnetic field is one of a gap alternating longitudinal magnetic field, a constant longitudinal magnetic field, a pulse longitudinal magnetic field, a sine wave longitudinal magnetic field and an alternating longitudinal magnetic field.
5. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 1, 2, 3 or 4, wherein the negative pressure restriction of electric arc comprises the following steps: the duty ratio of the gap alternating longitudinal magnetic field is 10-60%, and the frequency of the gap alternating longitudinal magnetic field is 1-30 Hz.
6. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 1, characterized in that: the included angle is 15-80 degrees, and a welding wire is fed into a welding area in a paraxial wire feeding mode; according to the performance of the additive manufacturing material, a hot wire or cold wire mode is adopted to feed the welding wire into a welding area; the welding wire is one of a solid welding wire, a flux-cored welding wire and a powder-cored welding wire.
7. The argon tungsten-arc additive manufacturing method based on negative arc pressure constraint of claim 1, wherein the method comprises the following steps: the argon tungsten-arc additive manufacturing method comprises the following process parameters: the diameter of a tungsten electrode is 1.2-6 mm, the additive manufacturing current is 40-450A, the length of an additive manufacturing arc is 1-4.8 mm, the additive manufacturing voltage is 8-65V, the additive manufacturing speed is 10-600 cm/min, the diameter of an additive manufacturing welding wire is 0.6-4.0 mm, the wire feeding speed of additive manufacturing is 10-800 cm/min, the additive manufacturing efficiency is 0.1-5 Kg/h, the flow rate of protective gas is 10-80L/min, the protective gas is one of mixed gas of 99.99% of argon, 99.99% of helium, 99.99% of argon and 99.99% of helium, and the interlayer temperature of additive manufacturing is controlled to be 100-400 ℃.
8. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 1, characterized in that:
when the additive manufacturing current is 100A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.02T, and the arc pressure of the arc center is 0 Pa;
when the additive manufacturing current is 120A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.022T, and the arc pressure at the center of the arc is 0 Pa;
when the additive manufacturing current is 150A and the arc length is 3mm, the critical value of the external longitudinal magnetic field intensity is 0.026T, and the arc pressure of the arc center is 0 Pa.
9. The argon tungsten-arc additive manufacturing method for negative pressure restriction of electric arc according to claim 1, characterized in that: the electric arc force of the electric arc is attractive, the molten drops are subjected to molten drop transition under the action of the electric arc attractive force, the electric arc has the attractive effect on a molten pool, and the electric arc is used for additive manufacturing of low-carbon steel, alloy steel, stainless steel, armor steel, bearing steel, die steel, aluminum alloy, titanium alloy, magnesium alloy, copper alloy, high-temperature alloy, high-entropy alloy, refractory metal and single crystal material.
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| LU503409A LU503409B1 (en) | 2022-04-19 | 2023-01-31 | Negative arc pressure constricted gastungsten arc welding (gtaw)-based additivemanufacturing (am) method |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115415646A (en) * | 2022-09-06 | 2022-12-02 | 上海工程技术大学 | Preparation method of medium-entropy/high-entropy alloy cladding layer |
| CN115415639A (en) * | 2022-09-06 | 2022-12-02 | 上海工程技术大学 | Surface deposition method based on double-tungsten-electrode coordinated control swing arc |
| CN115488540A (en) * | 2022-10-11 | 2022-12-20 | 江苏理工学院 | High-entropy alloy powder-cored welding wire and method for preparing high-entropy alloy coating by arc cladding |
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| CN115415639A (en) * | 2022-09-06 | 2022-12-02 | 上海工程技术大学 | Surface deposition method based on double-tungsten-electrode coordinated control swing arc |
| CN115488540A (en) * | 2022-10-11 | 2022-12-20 | 江苏理工学院 | High-entropy alloy powder-cored welding wire and method for preparing high-entropy alloy coating by arc cladding |
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